Electric hammer



Aug. 21, 1951 F. TAMBORELLO 2,555,279

ELECTRIC HAMMER Filed July 22, 1949 E l I IN VEN TOR.

62ml 5ML/5MM@ Patented Aug. 21, 19511 UNITED STATES PATENT OFFICEELECTRIC HAMMER Frank Tamlicrello, Milwaukee, Wis. Application July 22,1949, serial No. 106,267

5 Claims-V 1 This invention relates to improvements in electric hammers.

Electric hammers as heretofore developed have been very useful and laborsaving devices. They have not, however, been usable in many applicationsbecause of the bulkiness of said devices which prohibited their use inlimited or in constricted spaces. Prior electric hammers have been ofcomplicated construction and have used coil springs in conjunction withthehammer plungers thereof. Coil typ-e springs necessarily resulted inbulkiness of the complete hammer assemblage.

It is a general object of the present invention to provide an electrichammer which is of such shape that it is adapted for use in constrictedplaces which were heretofore inaccessible for con= ventional electrichammers.

A further object of the invention is to provide an electric lhammer ofthe class described which has a body section of relatively smallcross-sectional size.

A further object of the invention is toprovide a hammer of the classdescribed which `reduces operation fatigue by reason of havingrelatively few working parts at the hammer plunger end thereof. Y Afurther object of the invention is to provide a hammer of thel classdescribed which is particularly well adapted for auto body and fenderwork. by reason of its being provided with an lelchgated supportinghousing or body.

A further object of the invention is to provide a hammer of the classdescribed which employs a band spring in conjunction with the hammerplunger, rather than a coil Spring.

A further Obiet 0f the invention to, provide a hammer of the classdescribed whicllis YSQ ,con-2 Structed that the hammer plunger and theband Spring coactins therewith can be quickly removed from the assemblyby removing a readily reviewA able cover for a portion ofthe hammerhousing.

A further object of the invention is to provide a hammer of the classdescribed having an elongated drive shaft formed with a double camportion adjacent one end, said cam portion driving'ly engaging a hammerplunger which extends at substantially a right angle thereto.

A further object of the invention is to provide a hammer of the classdescribed wherein the drive shaft cams each engage different pcrtions ofthe hammer plunger.v

A further object of the invention is to provide an electric hammer ofthe class described which is simple in construction, easy andinexpensive to manufacture, and which is otherwise well adapted for thepurposes described.

With the above and other objects in view, the invention consists of theimproved electric hammer and all of tsparts and combinations, as setforth in the claims and all equivalents thereof.

In the drawing accompanying and forming a part of this specicationwherein is shown one complete embodiment of the preferred form of theinvention, and wherein the same reference characters indicate the sameparts in all of the views:

Fig. 1 is a side elevational view of the improved hammer with partsbroken away and shown in longitudinal vertical section;

Fig. 2 is a transverse vertical sectional view taken approximately alongthe line 2 2 of Fig. 1; and

Fig. 3 is a transverse vertical, sectional view taken along the line 3-3of Fig. 1.

Referring more particularly to the drawing, `the numeral 5 indicates anelongated tubular housing kor supporting member having connected to oneend thereof, as by the flanged connection shown, an electric motor Ii.The motor 6 is formed with. a manually engageable handle i which may beprovided with a trigger type electric switch 8 for controlling the motoroperation.

At the opposite end of the housing e is fixed .a shaft bearing 9 inwhich is `rotatably supported one end of an elongated drive shaft I0which projects from and is driven by the motor E. Adja cent the endthereof mounted in the bearing S, the shaft Iii is formed with one ormore cams I i, preferably as shown. The drive shaft Ill may loe Iformedof two sections which may be connected by va coupling I0'.

The housing 5 has a cut-away upper portion i?! extending from a pointintermediate its length to the end adjacent the vbearing 9, as shown. A.cover I3, having a generally U-shaped cross sec-- tion, is removablyconnected to the housing 5 and fits over the cut-away portion I2thereof, there "being suitable connecting means, such as screws VI 4 formaking said connection.

The cover I3 is formed with a bearing sleeve or boss I5 adjacent thecams II of the shaft Iii. A hammer plunger I6 is slidably positioned inthe, bearing boss and is formed with an external head Il. Rei'llovably`fixed at one end to intermediate upper portion of the cover iii acantilever leaf or band spring I8 which extends ansularlv toward thebearing 9 and rests thereon as shown. The spring lI8 is preferablywelded to the inner end of the hammer plunger I6, as shown, and isprovided on its opposite side with an integral metallic pad I9 having anarcuate surface which is held by said spring in contact with the cams IIof the drive shaft Il). The hammer plunger I6, the pad I9 and the springI8, therefore, form a single unit, and the pad I9, in effect, acts asthe head of the plunger It for engagement by the cams II.

In operation, as the drive shaft I is rotated, one of the cams II pushesthe hammer plunger I outwardly and also thereby deects the spring I8. Asthe cam I I continues to rotate, it moves away from the pad I9 andpermits the spring I8 to retract the hammer IS. Upon such retraction,the other cam II engages the pad I9 and pushes it outwardly for the nextoscillatory movement.

The improved hammer, by reason of its small cross-sectional size, iswell adapted for use in many places where only a limited amount ofworking space is available. By removing the cover I3, the hammer plungerand the spring I8 are simultaneously removed therewith, therebyfacilitating quick inspection or replacement of said parts.

The elongated shape of the housing 5 permits the improved hammer to beused by one operator in many applications where formerly two operatorswere required. For example, in auto fender Work, the operator can holdthe hammer against the under side of the fender and observe the work asit progresses from the upper side. With conventional hammers it isfrequently necessary for the auto wheels to be removed and for oneoperator to be underneath the fender to hold the hammer while a secondworkman observes the progress of the work from the upper or outer sideof the fender.

The likelihood of failure of the hammer plunger is greatly reduced inthe improved hammer due to the fact that each of the cams II does notengage the same point on the pad I9.

Frictional heat which may `cause hammer plunger failure is therebygreatly reduced.

Various changes and modifications may be made without departing from thespirit of the invention, such as changes in the specific structuralassociation of the plunger I6 with the spring I8 and the cams II, andall of such changes are contemplated as may come within the scope of theclaims.

What I claim is:

1. In an electric hammer, an elongated tubular housing having a cut-awayupper portion adjacent one end; an elongated longitudinally extendingcover for said cutaway portion removably connected to said housing, adrive shaft extending longitudinally of and rotatably supported in saidhousing; a hammer plunger, said cover having means for slidablysupporting said plunger at an angle to said drive shaft; at least onecam on said drive shaft engageable with said plunger to cause axialmovement of the latter upon rotation of said shaft; and a leaf springconnected to said cover and extending longitudinally of the housing forurging said plunger into engagement with said cam.

2. In an electric hammer, an elongated tubular housing having a cut-awayupper portion adjacent one end; an elongated longitudinally extendingremovable cover for said cut-away portion connected to said housing, adrive shaft eX- tending longitudinally of and rotatably supported insaid housing; a hammer plunger, said cover '4 having means for slidablysupporting said plunger at an angle to said drive shaft; at least onecam on said drive shaft engageable with said plunger to cause axialmovement of the latter upon rotation of said shaft; and a leaf springconnected to said cover and extending longitudinally of the housing andintegral with said plunger for urging said plunger into engagement withsaid cam.

3. In an electric hammer: an elongated tubular housing having a cut-awayportion adjacent one end; a cover for said cut-away portion removablyconnected to said housing; a sectional drive shaft extendinglongitudinally of and rotatably supported in said housing, said housingcut-away portion being of sufficient length to provide for removal ofone of said drive shaft sections therethrough; an axially slidablehammer plunger carried by said removable cover at an angle to said driveshaft; at least one cam on the removable section of said drive shaft andengageable with said plunger to cause axial movement of the latter uponrotation of said shaft; and a leaf spring carried by said removablecover and extending longitudinally of the housing for urging saidplunger into engagement With said cam.

4. In an electric hammer: an elongated tubular housing having a cut-awayportion adjacent one end; a cover for said cut-away portion removablyconnected to said housing; a sectional drive shaft extendinglongitudinally of and rotat ably supported in said housing, said housingcutaway portion being of sufficient length to provide for removal of oneof said drive shaft sections therethrough; an axially slidable hammerplunger carried by said removable cover at substantially a right angleto said drive shaft; at least one substantially U-shaped cam formed onthe removable section of said drive shaft and engageable with saidplunger to cause axial movement of the latter upon rotation of saidshaft; and a leaf spring carried by said removable cover and extendinglongitudinally of the housing for urging said plunger into engagementwith said cam.

5. In an electric hammer: an elongated tubular housing having a cut-awayportion adjacent one end; a cover for said cut-away portion removablyconnected to said housing; a sectional drive shaft extendinglongitudinally of and rotatably supported in said housing, said housingcutaway portion being of sufficient length to provide for removal ofsaid drive shaft sections therethrough; an axially slidable hammerplunger carried by said removable cover; at least one substantiallyU-shaped cam formed on the removable section of said drive shaft andengageable with Said plunger to cause axial movement of the latter uponrotation of said shaft; and a leaf spring carried by said removablecover and extending longitudinally of the housing and integral with saidplunger for urging said plunger into engagement with said cam.

FRANK TAMBORELLO.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

